1. Field of the Invention
The present invention relates to a light source module, a method for driving the light source module, and a display device having the light source module, and more particularly, to a light source module divided into several regions for a display device, wherein brightness dimming is performed on each light source block depending upon the brightness of adjacent light source blocks.
2. Description of the Related Art
Generally, liquid crystal displays (LCDs), a type off flat display panels, contain liquid crystal pixels that are not self-luminous. Therefore a separate light source module (e.g., backlight unit) is one of the key components of a liquid crystal display (LCD). LCDs display an image by filtering light emitted from a separate light source module (e.g., a backlight). The light source module includes a light source and a light source driver driving the light source.
Conventionally, a light source module provides light with uniform brightness over the entire surface of the flat display panel. This generally degrades the contrast ratio of the display panel. When the display panel displays an all-black image, the light source module still generates light with uniform brightness and there is typically some light leakage through or around the pixels of the display panel. Furthermore, the light source module typically consumes the most power of all the components of the display.
Therefore, efforts have been made to divide the total screen area of the display panel into a plurality of regions (blocks) having the same size, and providing a plurality of brightness control (i.e., a brightness dimming) circuits to independently control the brightness in each region. To this end, the light source module includes a plurality of light source blocks corresponding to the respective display regions. In this way, light leakage of the display panel is reduced and the power consumption is reduced. To independently perform the brightness dimming on each region, the brightness value of each region is independently calculated using an average gray level value (average gray level) of an image signal provided to each region. The independently calculated brightness value of each region is used for independently dimming the brightness of the light which the light source module provides to each region. Since the respective regions independently receive light with the corresponding brightness, a significant brightness difference exists along linear (e.g., top, bottom, right side, and left side) boundaries of the regions. Such a brightness difference can cause brightness spots. The brightness spots degrade the image displayed by the LCD.